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Who's Who at NASA: Jack Vieira, Range Project Manager

Friday, 04 May 2012

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In March of 2012,
NASA successfully launched five rockets from its Wallops Flight
Facility in Virginia. The launch was part of NASA's Anomalous
Transport Rocket Experiment, or ATREX, which will help scientists
better understand the jet stream. Jack Vieira, range project manager
for the ATREX mission, helped to launch five suborbital rockets more
than 60 miles above Earth.

NASA Tech Briefs:
Jack, let's set the stage here. Can you take us through what happened
on Tuesday, the day that the rockets launched? (March 24th)

Jack Vieira: We had a very
dynamic operation that night. We knew that we were going to have some
difficulties with winds that evening, so we set up a little bit later
than we would typically. We had a launch window from midnight until 5
am, and we knew the winds were going to be strong, but hopefully
dissipating somewhat as the evening progressed. In anticipation of
that, we opened a window at 0200 local, rather than midnight. We
still had very strong winds at that time. We were really concerned if
we would be able to get the rockets off that evening. Luckily the
wind gods were smiling down on us, and at the very end of the window,
we did a Hail Mary pass, and we were able to get the rockets off.

NTB: So the wind didn’t affect the
rockets?

Vieira: We had two rockets with
attitude control systems, but most of the rockets are point-and-shoot
type rockets. We have to do wind wading, where we launch a bunch of
balloons: a four-and-a-half hour balloon, that goes up to
100,000-plus feet, and then a mid-altitude balloon up to 50,000 feet.

At one hour and 15
minutes, we start launching balloons every 15 minutes. We’re
capturing data as it goes up. We have a column of air from the
surface all the way up to 100,000 feet, with the definitions, with
the velocities, and directions of the winds. With that, we calculate
what the azimuth and elevation settings should be, so that we can
anticipate how the winds are going to affect the rockets.

For example, if we
had strong winds and we were going to launch 100 degrees azimuth at
an 87-degree elevation, our wind corrections would change that. We
could change that as much as 30 degrees on azimuth to make the
corrections, so that it actually flies to 100 degrees.

NTB: What are the goals of the ATREX
mission? What are you trying to discover?

Vieira: The PI, Dr. Miguel
Larsen from Clemson University, had made a proposal to NASA
headquarters, and got it approved. They noticed that way back in the
1960s, and then more recently with the shuttle missions, that in the
higher altitudes, the 60-65 mile altitudes, there were extremely high
winds (between 200- and 300-mph winds), and they just didn’t
understand the dynamics there. Why was that happening?

Then also, there
was the fact that those altitudes, some of the communications with
satellites and such, were being distorted some, so they were trying
to get a better understanding of what happens at those altitudes that
create those kinds of winds.

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